1. Field of the Invention
The present invention relates to an apparatus for dispensing an adhesive tape to be stuck on a web, such as cigarette paper or tip paper, which is used in manufacturing, for example, cigarettes, cigarette filters, etc., and more specifically, to an adhesive tape dispensing apparatus with improved reliability, used in an apparatus that separates a double-sided adhesive tape from one side of a seal and sticks it on the web.
2. Description of the Related Art
Conventionally, in manufacturing filter cigarettes, for example, webs, such as belt-shaped cigarette paper, tip paper, etc. are supplied in succession. Each web is provided in the form of a roll, and it is let out or delivered continuously from the roll. When this roll is exhausted, another roll is set in a delivery apparatus, and the leading end portion of a web from the new roll is connected to the trailing end portion of a web previously delivered from the first roll. In this manner, the web can be supplied to a cigarette manufacturing apparatus or the like without interruption.
In general, a double-sided adhesive tape is used to connect the webs. It is stuck on a belt-shaped seal to form an adhesive tape laminate as a whole. The laminate, including the seal, is cut into pieces of a predetermined length. One of the adhesive tape pieces is stuck on one of the webs, and the seal is separated thereafter. Then, the other web is put on the tape piece so that the two webs are connected by means of the double-sided adhesive tape piece.
Since the double-sided adhesive tape is sticky, however, the cut tape piece is not easy to handle, and it is difficult to automate adhesive tape supply in a web connecting apparatus.
Described in Jpn. Pat. Appln. No. 3-311391 is an adhesive tape dispensing apparatus, which can automatically supply an adhesive tape in connecting webs without involving the aforesaid problem. FIGS. 1 and 2 schematically show an arrangement of this apparatus.
In FIG. 1, numerals 1a and 1b denote, respectively, a previously delivered web and a new web that is to be connected to the trailing end portion of the web 1a. The web 1a is delivered from a roll and fed past a pressing/cutting mechanism 2. The mechanism 2 includes a pressing member 3, which cuts and presses the trailing end portion of the web 1a.
The new web 1b is drawn out from its roll by means of a draw-out mechanism (not shown), hangs plumb down, and is fed downward by means of a suction conveyor mechanism 4. The mechanism 4 includes an endless belt 5, which is formed of an air-permeable material, and is decompressed to a negative pressure inside. As the belt 5 travels, therefore, the web 1b is fed downward with its leading end portion attracted to the belt 5 by suction under the negative pressure.
An adhesive tape dispensing mechanism 6 is located in the vicinity of the suction conveyor mechanism 4. The mechanism 6 is provided with an adhesive tape roll 7 that is prepared by rolling an adhesive tape laminate 12. The laminate 12 delivered from the roll 7 is run past guide rollers 8 and 10 and a roller 9 and wound up on a tape reel 11. The adhesive tape laminate 12 is formed by sticking a double-sided adhesive tape 15 on one side of a belt-shaped seal 14, as shown in FIG. 2, and is delivered with the tape 15 outside the roller 9.
The adhesive tape dispensing mechanism 6 comprises an adhesive tape cutter mechanism 13. The mechanism 13 includes a cutting knife 16, which faces the tape-side surface of the delivered adhesive tape laminate 12 and is located so as to cross the laminate 12. The knife 16 is designed so that it can be pressed against the double-sided adhesive tape 15 under a predetermined pressure and reciprocated in the transverse direction of the laminate 12 or in the direction of the edge of the knife 16.
In the adhesive tape dispensing mechanism 6 arranged in this manner, the cutting knife 16 is pressed against the double-sided adhesive tape 15 and oscillated in the direction of its edge, whereupon only the tape 15 is cut to form a cut portion C, as shown in FIG. 2.
Subsequently, the whole adhesive tape dispensing mechanism 6 advances, and the double-sided adhesive tape 15 of the adhesive tape laminate 12, guided along the outer peripheral surface of the roller 9, is pressed against the leading end portion of a new web 1b. Then, the entire mechanism 6 moves down, whereupon the roller 9 rolls along the web 1b. As a result, a double-sided adhesive tape piece 15a of a predetermined length, obtained by cutting the laminate 12 guided along the outer peripheral surface of the roller 9, is stuck on the surface of the web 1b and separated from the seal 14.
Then, the web 1b, having the tape piece 15a stuck thereon, is moved downward by the suction conveyor mechanism 4, and is lapped on the trailing end portion with the previously fed web 1a. Thereupon, the pressing member 3 of the pressing/cutting mechanism 2 advances, thereby pressing the webs 1a and 1b so that the webs are connected by means of the tape piece 15a and cutting an odd end of the trailing end portion of the web 1a.
According to the adhesive tape dispensing mechanism 6 constructed in this manner, the tape piece 15a from the double-sided adhesive tape 15 can be automatically stuck on the web 1b, and the webs 1a and 1b can be automatically connected to each other.
However, the operation and construction of this adhesive tape dispensing mechanism are complicated. In this apparatus, the tape piece 15a is stuck on the web as the roller 9 rolls on the web. If the web is a highly flexible thin web, such as cigarette paper, therefore, it may possibly be dislocated or crumpled. The cigarette manufacturing apparatus, in particular, is a large-scale system that produces cigarettes in large quantities. In the case where the web connection is unsuccessful, it takes a lot of time to stop the whole apparatus, remove defective joints, and restart the operation, so that the operating efficiency of the apparatus is lowered. Accordingly, there has been a demand for an additional improvement in reliability of the adhesive tape dispensing mechanism of the type described above.